title: Formation of silicon centered spirocyclic compounds: reaction of N-heterocyclic stable silylene with benzoylpyridine, diisopropyl azodicarboxylate, and 1,2-diphenylhydrazine.
abstract: Three silicon centered spirocyclic compounds 1-3, possessing silicon fused six- and five-membered rings have been prepared by the reaction of NHSi (L) [L = CH{(C=CH(2))(CMe)(2,6-iPr(2)C(6)H(3)N)(2)}Si] with benzoylpyridine, diisopropyl azodicarboxylate, and 1,2-diphenylhydrazine, respectively, in a 1:1 ratio. The three spirocyclic compounds (1- 3) were obtained by three different pathways. The reaction of L with benzoylpyridine leads to the activation of the pyridine ring, and dearomatization occurred. Treatment of diisopropyl azodicarboxylate with L favors a [1 + 4]- rather than a [1 + 2]-cycloaddition product, and the azo compound was converted to hydrazone derivative. Finally the reaction of 1,2-diphenylhydrazine and L results in the elimination of hydrogen by activating one of the C-H bonds present in the phenyl ring. All three complexes 1- 3 were characterized by single crystal X-ray structural analysis, NMR spectroscopy, EI-MS spectrometry, and elemental analysis. In addition the optimized structures of probable products and possible intermediates were investigated using density functional theory (DFT) calculations.
authors.affiliation: Institut für Anorganische Chemie, Universität Göttingen, Göttingen, Germany.
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Azhakar
authors.forename: Sankaranarayana Pillai
authors.initials: SP
authors.lastname: Sarish
authors.forename: Gasper
authors.initials: G
authors.lastname: Tavcar
authors.forename: Herbert W
authors.initials: HW
authors.lastname: Roesky
authors.forename: Jakob
authors.initials: J
authors.lastname: Hey
authors.forename: Dietmar
authors.initials: D
authors.lastname: Stalke
authors.forename: Debasis
authors.initials: D
authors.lastname: Koley
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D002219:Carbamates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010659:Phenylhydrazines / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D002219:Carbamates; D006571:Heterocyclic Compounds; D017646:Organosilicon Compounds; D010659:Phenylhydrazines; D011725:Pyridines; D012821:Silanes; D013141:Spiro Compounds; C032041:1,2-diphenylhydrazine